Chicano hippies playing mariachi music. That was my first impression of Los Lobos when I first saw the band back in the mid-1970s, before it had any albums out.

By that time, Los Lobos had already been a garage-rock band, so it was in the midst of falling back on our parents' music, having discovered just how complex it was. These guys dug deep into rancheras, son jarochos and guapangos to find the sources of the music for themselves — and, by extension, other Baby Boomer Mexican-Americans who were calling themselves Chicanos.

For their first independently released album in 1978, they played that folk music and called themselves Los Lobos del Este de Los Angeles. The band was a staple at parties when I was in college. Then, in 1983, Los Lobos' first EP (...And a Time to Dance) fired a warning shot to rock music, suggesting impending change.

Released a year later, Los Lobos' breakthrough album — How Will the Wolf Survive? — made it clear to everyone who heard it that loving The Rolling Stones as much as Flaco Jimenez was as natural as loving the Stones and, say, Woody Guthrie.

It felt as if they were writing music from my life: Los Lobos' Grammy-winning "Anselma" reminds me of my aunts spinning me around the dance floor as a kid at family parties; I can smell my mom's coffee in the background of songs like "Saints Behind the Glass"; they bridged the gap between themselves and another passion of mine when they covered The Grateful Dead's "Bertha," complete with Cajun accordion fills; and they made me proud when they made a hit out of "La Bamba," an old Mexican folk song that my dad played to my brothers and me when we were kids (not to mention the countless times I played it as a teenager in a Mexican wedding band).

It's mind-boggling to think that the group is celebrating its 40th anniversary this year. In our chat during this Guest DJ discussion, band members Louie Perez and Steve Berlin explain that the exact date is lost to history, but say they can trace their roots back to the period between Thanksgiving and Christmas.

We take time to dig deep into the DNA of Los Lobos by asking Perez and Berlin to bring in their own favorite tracks — mariachi, R&B, soul, blues. If we'd had more time, we'd have heard bluegrass, blues and folk music from both sides of the U.S./Mexico border.

In other words, it's just another day of listening to the sound of Chicano life in America. We have Los Lobos to thank for bringing it all together in vital, enriching music. Here's to the next 40 years.